#pragma once

#include<stdio.h>
#include<stdlib.h>

typedef struct BinaryTreeNode
{
	struct BinaryTreeNode* left;
	struct BinaryTreeNode* right;
	int val;
}BTNode;

BTNode* BuyNode(int x);

void PreOrder(BTNode* root);
void InOrder(BTNode* root);
void PastOrder(BTNode* root);

int TreeSize(BTNode* root);
int TreeLeafSize(BTNode* root);
int TreeKLevelSize(BTNode* root, int k);